Triplanal speaker enclosure



Oct. 11, 1960 W. A. RICE TRIPLANAL SPEAKER ENCLOSURE Filed Aug. 16, 1957ATTORN EYS United States Patent 2,955,669 TRIPLANAL SPEAKER ENCLOSUREWarren A. Rice, 10015 W. Huron River Drive, Dexter, .Mich., assignor ofone-half interest to Carl E. Grebe,

Midland, Mich.

Filed Aug. 16, 1957, Ser. No. 678,672 8 Claims. (Cl. 181-31) The presentinvention relates to speaker enclosures and more particularly to atriplanal hanging speaker enclosure. The invention provides a highefliciency speaker enclosure requiring an absolute minimum in amount ofspace while providing a high efficiency speaker to air coupling in asinexpensive a manner as possible.

In United States Letters Patent 2,754,926 I disclosed and provided aspeaker enclosure of the Corner Horn type having the maximum efiiciencyof any compact speaker in the low frequency audio range. The presentenclosure, while not equaling the low frequency audio efiiciency of thatstructure, does provide, on a pound for pound basis a highly efiicientstructure particularly adaptable where walls are cluttered andobstructed or where living space is at a premium. As in my United StatesLetters Patent 2,754,926, the walls of the room are utilized as aneffective extension of the enclosure or horn. As in my prior work thisenclosure approaches the exponential formula for theoretically perfectlow frequency sound reproduction but employs a straight taper flare.

The hanging horn has been known in the art for years but little has beendone to analytically improve its function.

It is there-fore among the objects of this invention to provide ahanging horn of vastly improved audio efficiency for high fidelity soundreproduction in the low frequency ranges.

Another object is to provide a hanging horn which closely approaches inits audio efliciency horns of great size approximating the theoreticalexponential formula. Another object is to provide a simple inexpensivespeaker enclosure structure which utilizes two walls and a ceiling assound bafiles in a position not normally obstructed.

I Other objects including economy of material and amenability to plasticcasting, for example, will become increasingly apparent to those skilledin the art as the description proceeds.

.In the drawing:

Figure 1 is a side perspective view of a hanging speaker enclosureisolated from a room corner to reveal the simplicity of its structure.

Figure 2 is a frontal perspective view of a hanging speaker enclosure inaccord with the present invention positioned in the corner of a roomproximate to the ceiling of the room.

Figure 3 is a top plan view of the hanging enclosure indicating therelative location of side walls and spacers in respect to speakerlocation.

Figure 4 is a front view through the speaker axis to reveal the simpleinterior construction.

Figure 5 is a perspective view of the speaker enclosure of the presentinvention adjacent the floor and two adjacent converging walls orplanes.

Figure 6 is a transverse section through the hanging closure taken online VI-VI of Figure 4.

Patented Oct. 11, 1960 2 General description In general, the presentinvention comprises a hanging speaker enclosure for a back loadedspeaker. In such structures the audio coupling in the bass or lowfrequency ranges emanate principally in the sound column set in motionbehind the speaker. The flare rate for movement of such a column shouldclosely approximate known exponential formulae.- In the earliest horns,Where the formula was carried out as far as practicable the enclosure orhorn occupied a substantial amount of space in a relatively largethreatre. Subsequent folded approximations of the formulae met withvarying degrees of success and managed to minimize the space required atsome sacrifice of efficiency so that the enclosure would fit intomoderate sized dwelling rooms. It was subsequently found that thedistortion in such horns reduced their fidelity in the low frequencyaudio range inasmuch as the sound column was joggled around numerouscorners before being finally emitted to the room. The unfolded horn wasdeveloped to counteract such distortions but lacked full flare extensionbecause the room walls extended only to ceiling height by carrying theprojected exponential column. The present structure utilizes ceiling orfloor and wall extension from a corner as planal flare projectionassisters. The present structure comprises three substantially identicalplanal wall pieces and three taper spacers. A triangular mounting boardhaving an opening therethrough for the mounting of a back-loaded speakerat once lends excellent stability to the three wall pieces and ismuffled to avoid resonance problems from the speaker. The wedge-likeside pieces are curved at their outer faces and have curvilineartruncations at each apex to provide a satisfactory communicating columnor throat space between speaker and flare. Thus, a triplanal enclosureis provided and is positioned by tapered spacers to define, whenmounted, three right angle merged columns of sound projectedsimultaneously at selected straight tapered flare rates. As will be seenand appreciated the device of the present invention is extremely simple,compact, and is of light weight.

Specific description Referring more specifically to the drawing, Figure2 shows the preferred operative setting of the triplanal horn or speakerenclosure 11 at the juncture of ceiling 12, and intersection of walls 13and 14. As the description proceeds it will be apparent that the speakerenclosure or horn 11 is also adaptable to the corner juncture betweenwalls 13 and 14 and floor (Figure 5). A frontal drape 15 (Figure 1)covers the flared portion of the horn 11 and may be decorated asdesired. In Figure 2 the structure of the horn 11 is best revealedindicating three segment-like planal members 16, 17, and 18 joined attheir abutting edges. Substantially adjacent to the apex portion of saidsegments an arcuate truncation 19,- 2t) and 21 (in respectivecorresponding order of numbered segments) provides an opening or throat22. On the exterior of each of the planal segments 16, 17 and 13 arewedge-like or tapered extensions 23, 24 and 25, each perpendicular tothe plane of the members 16, 17 and 18 and joining the planal members16, 17 and 18 on the approximate bisecting line of said segments runningfrom the approximate apex to the curvilinear mouth edges 26, 27 and 28.As will be seen these extensions form fins or spacers 23, 24 and 25provide a selected flare as between adjacent planal walls when the horn11 is in operating position. A triangular mounting board 29, having acenter opening 30, there-through into a forward compartment and arearward compartment. The mounting board 29 thus forms a plane having anopening 30 therethrough which is transverse to the central axis of theenclosure 11. The mounting board 29 is provided with mounting means 32for a desired speaker 33. The preferred form of speaker is a coaxialback loaded type Well known in the art. The speaker 33, as shown, iscoaxially positioned in the enclosure 11.

While the description has viewed the construction of the enclosure 11from the object of describing the discrete parts of the enclosure, itwill be readily appreciated that the entire unit is designed foramenaoility to molding or casting, preferably in plastic material sothat the elements become integral except for the mounting panel 29 whichmay be removed for installation and service of the speaker 33.

A decorative acoustic covering 15 is tastefully secured to cover themouth opening 31 if desired. Suitable vibration dampening gaskets (notshown) and the like, may be employed in securing the panel 29 to theenclosure 11 and in securing the speaker 33 to the panel 29.

Operation The operational setting for the speaker enclosure 11 is in thecorner of a room adjacent the floor (Figure or preferably hangingadjacent the ceiling (Figure 2). In this manner the two walls and theceiling or floor become the flare extensions for the sound columnemanating from the rear of the speaker 33 through the throat 22. The

est sound reproduction from the enclosure described is obtained from thehanging of the enclosure from the room corner adjacent to the ceilinginasmuch as fewer obstacles are encountered in the projection of thesound column. Excellent fidelity in the audible low frequency range (16to 100 cycles per second) is experienced with adjustment in flare ratebeing accomplished by varying the taper in the spacers 23, 24, and 25 intheir contact with adjacent planal surfaces.

It will be appreciated from the foregoing that a considerable advance instructure is presented herewith if measured in terms of simplicity andoverall eificiencies measured against any known horn of the hangingtype.

Having thus described my invention it will be appreciated that certainmodifications within the skill of the art may be made. Suchmodifications are intended to be included herein if they fall within thescope of the hereinafter appended claims.

I claim:

1. In a speaker enclosure, the combination including: three planalsegments joined at their edges to form a triplanal enclosure; atransverse panel dividing said triplanal enclosure into a forwardcompartment and a rearward compartment and said panel having a centralopening therethrough for the mounting of a speaker; and a plurality ofadjusting fins extending exteriorly from said planal segments to provideselected spacing between said segments and adjacent planal surfaces.

2. In a speaker enclosure, the combination including: three planalsegments of substantially triangular shape joined at their edges to forma triplanal enclosure having an outwardly flaring mouth and a throatopening provided by a truncation occurring short of the apex of saidenclosure; a transverse panel intermediate said mouth portion and saidthroat portion of said enclosure, said panel having an openingtherethrough for peripheral mounting of a speaker; and a Wedge-likespacer extending from each exterior side of said enclosure spacing saidplanal segments with regard to adjacent plane surfaces.

3. In a hanging type speaker enclosure, the combination including: atriplanal enclosure having three substantially identical sides defininga flared triangular mouth opening and a smaller triangular throatopening at either end; a panel tranversely across the opening throughsaid triplanal enclosure intermediate said mouth and said throat, saidpanel having an opening therethrough for the axial attachment of aspeaker; and wedge-like spacers selectively extending from saidtriplanal enclosure spacing each segment of said enclosure from adjacentplane surfaces; and at least three intersecting plane surfaces againstwhich said spacers rest.

4. In a hanging type speaker enclosure for hanging in a corner where atleast three plane surfaces meet, the combination including: an openended triplanal enclosure comprised of three plane segmentssubstantially triangular in configuration and secured to each other attheir edges; a panel transversely across the central axis defined bysaid triplanal enclosure and intermediate the open ends thereof, saidpanel having an axial opening therethrough for axial accommodation of aback loaded speaker; fin-like projections extending exteriorly from eachof the said segments forming spacers establishing a selected flare rateas between planal segments and adjacent plane surfaces.

5. In a speaker enclosure the combination comprising: three identicalplanal segments joined at their edges to form a substantially triplanalenclosure having an opening through the apex; wedge-like spacersextending outwardly from said segments on a line bisecting saidsegments; and a triangular speaker mounting board fitted into the mouthof said triplanal enclosure and having a round opening therethrough forthe accommodation of a speaker.

6. In a speaker enclosure for mounting in a room at the juncture ofceiling and room corner, the combination comprising: a segment-likeceiling wall; a pair of similar segment-like side walls joined at theiredges to form a triplanal enclosure open at its apex; three Wedge-likespacers extending outwardly from said wall segments and positioned on aline bisecting said segments; a triangular planal mounting board spacedapart from said open apex and having a circular opening therethrough forthe mounting of a speaker.

7. In a speaker enclosure for positioning in the corner defined by threeintersecting plane surfaces converging Walls, the combinationcomprising: three segment-like planal walls having the apex of eachremoved and being joined at their straight edges to form a triplanalenclosure flaring outwardly at a uniform rate; three Wedgelike taperedspacers extending outwardly from said walls normal to a line bisectingeach of the said walls to space said walls a uniform distance from theceiling and sidewalls of a room and assure a uniform flare between saidenclosure Walls and the sidewalls and ceiling of said room; and atriangular planal speaker mounting panel truncating said triplanalenclosure forwardly of said apex in said enclosure and said panel havingan opening therethrough for the accommodation of a speaker.

8. In a speaker enclosure for a back loaded speaker, the combinationcomprising: three planal segments joined at their edges to form atriplanal enclosure; and defining a flared triplanal forward opening anddefining an opening at the apex of said triplanal enclosure, atransverse panel dividing said triplanal enclosure into a forward flaredopening and a rear compartment, and said panel defining a centralopening therethrough for mounting of a speaker; and a fin extendingoutwardly from each of said segments to provide selected spacing betweensaid planal segments and adjacent planal surfaces.

References Cited in the file of this patent UNITED STATES PATENTS1,586,659 Davis June 1, 1926 1,794,957 High Mar. 3, 1931 1,984,550Sandernan Dec. 18, 1934 2,206,012 Hart July 2, 1940 2,731,101 KlipschJan. 17, 1956

